questions about map this

sup everyone!
im new to the fourm,been doing alot of reading but im having a problem with map this.well its not really a problem just some questions.

ok i created a couple maps of my area.1 of the metro detroit which took over and hour on google maps and the other of sterling heights which took about 20 mins.

my question:can i link these maps together to make one map?or can you download a full state map and still be able to zoom in?
i did try to cut and paste my maps in the same folder but it didnt work.

i have a garmin gps(its a buddys)that im gonna download his maps and try to upload them on my psp.from what im reading i just have to convert the file so the psp or map this will read it,is this correct?has anyone done this yet?will u get the full state map?

thanks in advance dave...